@Scott ********
from the end of February until the end of May three countries, Laos, Myanmar, and Thailand, burn off their fields, and there are regular forest fires, with the weather patterns pushing all that smoke down over Chaing Rai and centering over Chaing Mai. It will be in the aqi range from about 150-250 over Chaing Rai, and hitting over 300 in Chaing Mai area. It gets bad enough in Chaing Rai that you can not see across the Mekong river. Just saying